JP2008197797A - Probe traffic information generation method - Google Patents

Abstract

A traffic jam point is estimated from communication information of a normal mobile phone without using GPS.
A processing unit 504 of a traffic information center analyzes communication information between a mobile phone and a base station in advance, and selects and registers a mobile phone having a movement pattern that can be used as a probe terminal for detecting traffic congestion. To do. Call volume distribution data for each time zone is created by obtaining an average call volume in the time zone of the selected mobile phone, for example, an average value for one month. Collect the real-time call volume for each registered mobile phone time zone, compare it with the normal call volume, and if the actual call volume has increased more rapidly than the normal call volume, the probe Estimate the location of the terminal mobile phone. The position estimation is performed by registering a road map 507 around the base station of the mobile phone in association with the position of each base station and matching with the road map. When the estimated position is concentrated at a certain location on the road to be matched, the corresponding location is estimated as a traffic jam point.
[Selection] Figure 1

Description

  The present invention relates to a probe traffic information generation method, and more particularly to a method and system for detecting traffic congestion using a mobile phone as an in-vehicle terminal of a probe car for collecting traffic information.

  In order to search for the shortest time route from the current location to the destination by using the navigation system of the automobile, it is necessary to obtain not only the map information but also the traffic congestion information of the planned route. In order to obtain this road traffic congestion information, it is necessary to monitor the movement of a car traveling on the road. There are two methods for calculating traffic information by monitoring the movement of automobiles: a method for calculating traffic information using a Vehicle Information Communication System (VICS) and a probe car equipped with GPS (Global Positioning System). There is a method of calculating based on the probe information. Here, the probe car means an automobile for collecting traffic information (probe information) by actually traveling on a road.

  In order to calculate traffic jam information by the traffic information system (VICS), it is necessary to install a roadside sensor on the road from which traffic information is acquired. Then, the speed and travel time of the vehicles passing under the roadside sensor are collected as road information data in the VICS center, and traffic information is generated based on the information.

  In order to acquire traffic information by this VICS, it is necessary to install a large number of roadside sensors on roads (national roads, highways, prefectural roads, etc.) nationwide. In addition, in order to generate traffic jam information with a probe car equipped with a GPS receiver, it is necessary to install the GPS receiver on the vehicle, and the number of probe cars (GPS equipped vehicles) that actually travel on the road. There are cost issues such as securing communication costs for communicating location information from the vehicle to the center.

  As a conventionally known traffic information related system, a probe car is used, and a traffic situation estimation method and a traffic situation estimation using probe information for realizing a traffic jam situation prediction / estimation in an area where the probe car is not currently running. A providing system has been proposed (see, for example, Patent Document 1). In the traffic situation estimation method and the traffic situation estimation / provision system described in Patent Document 1, each probe car transmits probe information, which is the time and position of the traveled area, to the center. The center accumulates probe information in the probe information database by the traffic condition estimating means, and uses the current probe information and the probe information database accumulated from the past to the present. Accordingly, the predicted traffic jam information in the front area of the probe car and the estimated traffic jam information in the rear area are estimated.

JP 2002-251698 A

  The traffic situation estimation method and the traffic situation estimation / provision system disclosed in Patent Document 1 are methods that utilize probe car data. A GPS receiver is installed in a target automobile in order to acquire probe information (position information of the automobile), and the position information obtained by the GPS receiver is transmitted to the probe center using communication means such as a mobile phone. The probe center accumulates the collected information and generates traffic information. Therefore, a GPS receiver is required in addition to the mobile phone, and communication costs for transmitting probe information from the vehicle to the center are incurred.

  The object of the present invention is to detect traffic jams and their points depending on the communication status (communication information of the base station with respect to the mobile phone) of the mobile phone as a probe terminal and communication with the base station without using GPS. It is to provide a system that can be estimated. Another object of the present invention is to provide a mobile phone position detection system that can detect the position of a mobile phone that can be used in a traffic jam detection system without using GPS.

  The present invention relates to a traffic jam detection method for detecting sudden traffic jams of automobiles on a road, based on communication information between individual mobile phones and base stations, a movement pattern that can be used as a probe terminal for traffic jam detection (steady state). A mobile phone having a mobile position) and registering a plurality of mobile phones selected as probe terminals and their normal call volume, and the call volume of the registered mobile phone in a specific time zone Estimate the location of those mobile phones when the call volume increases rapidly compared to the normal call volume, and if the estimated location is concentrated in a certain location on the road, the corresponding location It is characterized by estimating. The position of the mobile phone is estimated by matching with a road map registered in advance.

  According to the traffic jam detection method of the present invention, it is possible to detect a sudden traffic jam early without using GPS from the short-time communication status of a mobile phone used as a probe terminal. In particular, by utilizing the existing mobile phone base station equipment, it is possible to reduce the capital investment and generate traffic congestion information on a nationwide scale.

  The present invention has been made paying attention to the following points. Calling a driver's mobile phone while driving is prohibited by road traffic laws in Japan due to safety concerns. Calls can be avoided as much as possible even in countries that are not prohibited. On the other hand, drivers are expected to use more mobile phones, such as stopping their cars and making business communications when there is a concern about delays due to sudden traffic jams. Therefore, it is possible to detect sudden traffic jams by using such usage status of the mobile phone.

  In addition, some traveling automobiles have daily traveling areas such as commuting vehicles in the morning and evening, courier services during the day, and business vehicles. For example, it is considered that a commuting vehicle has a daily behavior pattern from home to work in the morning and from work to home in the evening (steady position movement) and has a direction. Furthermore, some drivers having such behavior patterns have a habit of using a mobile phone before and after driving. If the information about these behavior patterns is grasped from the communication status between the mobile phone and the base station, it is only possible to know the call point, and depending on the time of day, whether the call is related to traffic congestion on the road or the road Can be estimated.

  According to the above-described present invention, it becomes possible to generate road traffic information in various parts of the country by capturing such a behavior pattern of a driver who owns a mobile phone. In particular, it is possible to obtain the driver's traffic congestion information from roads where VICS cannot be used and cars where GPS cannot be used.

  Embodiments of the present invention will be described below with reference to the drawings. FIG. 2 is a schematic diagram of the traffic jam detection system of the present invention. A base station indicated by base stations 1 and 2 of a mobile phone is illustrated. The communication information of each mobile phone is communicated between the communication processing center 100 and the mobile phone or landline phone of the other party of communication via the nearest base station where radio waves reach.

  The range over which mobile phone radio waves reach often spans a plurality of base stations, that is, a plurality of communication areas. A base station that receives radio waves to a mobile phone performs communication for grasping the position of the mobile phone to the mobile phone during a call of the mobile phone. When a base station that can communicate with a mobile phone, that is, receives radio waves from the mobile phone, detects communication of the mobile phone, it transmits communication information up to the end of the call to the communication processing center 100, which is a host device.

  This communication information includes information obtained by encrypting the unique number of the mobile phone, approximate location information of the mobile phone, call start time, and end time. The location information of the mobile phone included in the communication information includes, for example, a propagation delay time of a communication signal (radio wave), sector information that divides the communication area of the base station into a plurality of parts, and the like.

  FIG. 9 shows one of the communication areas of the mobile phone base station. In the communication area of the base station S, a plurality of regions Z0, Z1, Z2, and Z3 corresponding to the signal propagation delay time with the base station S as a center are divided in a radial direction at predetermined intervals. The width (distance) R in the radial direction of each zone is about several hundreds of meters. With these zones, the approximate distance between the base station and the mobile phone can be known from the propagation delay time.

  The communication area is divided into a plurality of sectors based on the direction of each antenna of the base station (three sectors in FIG. 9). Based on the distance information and sector information between the base station and the mobile phone, the approximate position of each mobile phone can be grasped.

  Daily communication information between the mobile phone and the base station is sent to the communication processing center 100, which is a higher-level device of the base station, and further sent to the traffic information center 101 and stored in the database. The communication processing center 100 processes communication information sent from each base station and transmits it to the traffic information center 101.

  The traffic information center 101 receives the communication information from the communication information center 100, and creates road congestion information by a calculation process described later. This traffic jam information is supplied to an automobile information medium 120 (for example, a broadcast medium for car navigation, a service for mobile phones, a content provider for telematics, etc.) via an information providing medium.

  FIG. 1 is a block diagram showing the configuration of a traffic information center that forms the core of the traffic congestion detection system of the present invention. The input / output interface 502 of the traffic information center 101 acquires the communication information between the mobile phone and the base station from the communication processing center 100 and stores it in the communication information database 503.

  The arithmetic processing unit 504 analyzes (statistical processing) the communication information stored in the communication information database 503 every day in order to search for a mobile phone that can be used as a probe terminal for detecting traffic congestion. The search for available mobile phones will be described with reference to the principle explanatory diagram of the invention shown in FIG. 3 and the flowchart of FIG.

  For example, as shown in FIG. 3A, it is assumed that there are base stations S1, S2, and S3 adjacent to a section of a road including zones a to d. Further, as shown in FIG. 3B, it is assumed that a certain mobile phone has much communication in the zone a at 7 o'clock in the morning and much communication in the zone d at 18:00 in the evening. From such mobile phone communication information, it is presumed that the mobile phone owner is a commuter and travels by car between predetermined zones a to d during work hours and work hours. That is, this mobile phone has a movement (trip) pattern from zone a to zone d every day, and is an effective mobile phone terminal for the purpose of generating traffic information.

  FIG. 4 is a flowchart showing the operation of the arithmetic processing unit 504 of the traffic jam detection system. A mobile phone having the above movement pattern is searched by analyzing a trip end (zone A, zone B or the like is called a trip end) for each time zone of the mobile phone. That is, communication data is extracted from the communication information database 503 (step S10), and a mobile phone that is moving is extracted (step S11).

  To check the trip end, find the two main communication zones of the mobile phone's daily communication zone, and select the mobile phone terminal when the two zones are more than a predetermined distance (for example, 10 km). Select the probe terminal as available.

  The mobile phone searched for the availability of the probe terminal is registered in the available mobile phone database 505 by its identification number while maintaining anonymity (step S12). As described above, mobile phones that hardly move and mobile phones with low movement frequency are excluded from registration.

  Next, main trips of available mobile phones are extracted (step S13). That is, the trip ends of the available mobile phones selected and registered in step S12 are tabulated, and the frequent trip end pair units (a⇒d, c⇒a, etc.) are extracted. Then, an average value distribution of the number of times of communication for each time zone is periodically created (updated) from communication information (daily accumulated data) of a large number of mobile phones selected as probe terminals, and registered in the database 506 (step) S14). Selection and update of a mobile phone that can be used as a probe terminal is executed based on the latest accumulated communication information in a periodic cycle (for example, a one-month cycle).

  In addition, the arithmetic processing unit 504 analyzes the input communication information and stores the real-time call volume of the latest mobile phone (probe terminal) in the latest time zone in the database 508.

  In the database 507, a road map around each base station of the mobile phone is registered in association with the position of each base station. The database 509 stores mesh data (details will be described later) used for detecting traffic congestion points, and the database 510 stores information (identification information, location information, sector information, etc.) related to base stations.

  In FIG. 3, if a sudden traffic jam occurs in the middle of the mobile phone movement zone a to d at 7:30 on a certain day, the driver is more likely to be late and calls the workplace frequently. Become.

  As the number of drivers increases, the number of calls (call volume = call rate) at the base station S1, the base station S2, or the base station S3 is expected to increase significantly compared to normal times. In addition, it is the driver who moves from zone a to zone d that makes a call during this time period from the encrypted unique number of the mobile phone whose call volume increases. It is expected that many mobile phone owners registered as probe terminals are likely to be included.

In this embodiment, the arithmetic processing unit 504 includes an available mobile phone database 505, an average number of calls database 506, and a real-time traffic database 508.
Based on this information, it is determined whether or not the call volume of a mobile phone used as a probe terminal in a predetermined time zone has increased more rapidly than the normal call volume (average value distribution data).

  FIG. 5 shows a determination procedure by the arithmetic processing unit. The arithmetic processing unit 504 compares the average communication amount for each time zone with the real-time communication amount for each pair of trip ends (step S21). Then, when it is determined that the real-time communication amount is extremely large (a predetermined amount or a predetermined ratio or more than the average communication amount in the corresponding time zone) (step S22), sudden traffic congestion occurs at the trip end (zone section). (Step S23). As shown in the figure, the call volume (dotted line) between specific zones in a certain time zone (for example, a-d) has increased rapidly compared to the normal average value distribution call volume (solid line) in the corresponding time zone. If it is determined that there is a sudden traffic jam, it is determined.

  As described above, the occurrence of sudden traffic jam can be detected from the increase in the call volume at the trip end (zone section) where a mobile phone registered as a probe terminal is located. Next, a method for estimating the position of occurrence of congestion will be described. This position estimation involves matching with a pre-registered road map, and when the estimated position is concentrated at a certain location on the road to be matched, the location is estimated as a traffic jam point. .

  The position estimation of the mobile phone (probe terminal) for specifying the location of the traffic congestion point can be performed even by a mobile phone not equipped with GPS. For example, as shown in Japanese Patent Application Laid-Open Nos. 2000-2443827 and 2000-243828, a triangulation method that is a known position specifying method (used when the number of base stations that can be used for position calculation is 3 or more) Or 2 base station location calculation method. In the present embodiment, the following new position estimation method is proposed. This position estimation method will be described with reference to FIGS.

  If it is estimated that traffic congestion has occurred through the above-mentioned series of processing, specify multiple base stations (which can generate mobile phone communication information) that can receive radio waves from each mobile phone of the probe terminal To do.

  FIG. 10 illustrates the relationship between three base stations x, y, and z that receive radio waves from a mobile phone (probe terminal) P and their communication areas. The position of the mobile phone P can be estimated as an area portion in which each base station has three sectors, each sector including the position of the mobile phone P overlaps, and is determined by the resolution in the radial direction of each sector.

  The arithmetic processing unit 504 extracts road map information around the base stations x, y, and z from the road map information registered in the road map database 507. The extracted road map information is a road for which traffic information is to be provided. FIG. 6 is an explanatory view showing the transition of the target road map data, and FIG. 6A shows the extracted road map information.

  FIG. 7 is a flowchart showing the position estimation process. In step S70, the arithmetic processing unit 504 creates a map matching road map corresponding to the area around the base stations x, y, and z. And the mesh data stocked in the mesh data database 509 is taken out, and the object road map of Fig.6 (a) is quantized in mesh shape like FIG.6 (b). This mesh area is created in a positional relationship with the base stations x, y, z using coordinate information.

  In the mesh area, the matching plane is divided into a large number with a desired resolution (when converted to an actual distance, one mesh is 50 m square, for example). If there is a target road of the road map information in this mesh, as shown in FIG. 6C, identification information for identifying the road is added to the mesh corresponding to that part (the part shown in black). (Step S71 in FIG. 7). This process is repeated as long as there is distance information (delay information) from the base station in step S72 of FIG. If there is no distance information, the position calculation ends.

  In the case of the present embodiment, the number of mesh elements in the entire matching plane is 196, 79 of which correspond to road portions (FIG. 6C). Next, from the communication information data, the position of the mobile phone is calculated from the radio wave propagation delay times of the plurality of base stations x, y, z with respect to the mobile phone (probe terminal) P based on the communication information at the time when calls are concentrated. .

  FIG. 8 is an explanatory diagram showing a traffic jam point calculation process. FIG. 8 shows a curved line made up of elements filled with a mesh that is expected to have the position of the mobile phone in the mesh-like map plan view, and the number N of filled meshes. As shown in the delay information from the base station X in FIG. 8A, candidates are narrowed down to 12 elements painted in black. Next, as shown in FIG. 8 (b), candidates are narrowed down to four elements painted in black according to the delay information from the base station Y. Finally, as shown in FIG. Candidates are narrowed down to two elements painted in black according to the delay information.

  That is, by calculating the distance from each base station x, y, z to the mobile phone, and by calculating the intersection of circles with these distances as radii in the mesh map matching plane incorporating the road map information, Location estimation with map matching of the mobile phone is performed. By the above filtering process, it is displayed that the approximate position of the mobile phone P is the point P shown in FIG.

  In this case, the directionality of the traffic jam can be specified from the movement pattern of the mobile phone obtained from the communication information of the probe terminal. That is, the movement pattern includes position information for estimating movement and information on the directionality of movement, and the directionality of the traffic jam when the traffic jam point is estimated can be specified based on the information. For example, in the zone a to d in FIG. 3, from the distribution statistics of the communication position of the mobile phone, if it is 7:00, it goes to a⇒d, and if it is 18:00, it goes to d⇒a. Can be identified.

  In the actual processing for estimating the position of occurrence of traffic jam, the desired resolution and mesh size can be set as appropriate. According to the above method, there is an effect that iterative calculation such as the conventional position calculation processing by GPS can be greatly reduced.

The block block diagram of the traffic information center in the traffic congestion detection system by one Example of this invention. 1 is a schematic diagram of a traffic jam detection system according to the present invention. Explanatory drawing which shows the principle of the traffic congestion detection system of this invention. The flowchart which shows selection of the mobile telephone which can be used by one Example of this invention, and its communication information registration. The flowchart which shows the detection of the occurrence of traffic congestion according to one embodiment of the present invention. Explanatory drawing which shows the detection process of the traffic congestion position on a map. The flowchart which shows a traffic congestion point calculation process. Explanatory drawing which shows the filter process of congestion point calculation. Explanatory drawing which shows an example of the communication area of a mobile telephone base station. Explanatory drawing which shows the state which the communication area of three base stations has overlapped.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1, 2 ... Base station, 100 ... Communication processing center, 101 ... Traffic information center, 120 ... Automotive information media, 502 ... Input / output interface, 503 ... Communication information database, 504 ... Arithmetic processing unit, 505 ... Available mobile phone Database: 506: Average communication count database, 507: Road map database, 508: Real-time traffic database, 509: Mesh data database, 510: Base station database.

Claims (11)

In a traffic jam detection method for detecting sudden traffic jams on the road,
Search for mobile phones with a movement pattern that can be used as a probe terminal for detecting traffic jams from communication information between individual mobile phones and base stations, and select a plurality of mobile phones selected as probe terminals and their normal times. The call volume is registered, and when the call volume of a registered mobile phone in a specific time zone increases rapidly compared with the call volume in normal times, the position of those mobile phones is estimated and estimated. A traffic congestion detection method characterized in that when a certain position is concentrated at a certain location on the road, the location is estimated as a congestion location.   In Claim 1, the position of the mobile phone is estimated by overlapping zones of a plurality of base stations that receive radio waves of mobile phones whose call volume is rapidly increasing, and road maps registered in advance for these base stations. A traffic jam detection method characterized by matching.   2. The traffic congestion detection method according to claim 1, wherein the movement pattern is a regular pattern that is repeated in daily life, and is estimated to move by an automobile.   The traffic congestion detection method according to claim 1, wherein a mobile phone that can be used as the probe terminal periodically updates whether the mobile terminal has the usable movement pattern.   2. The movement pattern of each mobile phone used as the probe terminal according to claim 1 is obtained from communication information between the mobile phone and a plurality of base stations. And a traffic jam detection method for estimating the direction of the traffic jam when the traffic jam point is estimated based on the information. In Claim 2, the position of the mobile phone used as the probe terminal is:
Identifying a plurality of base stations to which radio waves of each mobile phone of the probe terminal reach, and subdividing the map matching plane corresponding to the peripheral area of the plurality of base stations into a mesh shape;
Extracting the road map information around the plurality of base stations from the registered road map information, and incorporating the extracted road map information into the mesh map matching plane;
The distance from the plurality of base stations to the mobile phone is calculated, and the intersection of circles with these distances as radii is estimated by the mesh map matching plane incorporating the road map information. How to detect traffic congestion.   7. The distance from the plurality of base stations to the mobile phone according to claim 6, wherein the distance between the plurality of base stations with respect to the mobile phone is differentiated in a radial direction within a communication area of each of the plurality of base stations. A traffic jam detection method that is calculated using the distance in the radial direction of a region that has been set. In a traffic jam detection system for transmitting communication information between individual mobile phones and base stations to a communication processing center, analyzing the communication information in the communication processing center and detecting traffic jam information,
The said traffic processing center detects a traffic jam using the traffic jam detection method in any one of Claims 1-7, The traffic jam detection system characterized by the above-mentioned. A communication information database for storing communication information between individual mobile phones and base stations;
An arithmetic means for analyzing the communication information and searching for a mobile phone having a movement pattern that can be used as a probe terminal for detecting traffic jams;
As a result of the search, an available mobile phone database for registering mobile phones selected as probe terminals,
A computing means for obtaining an average value of the call volume in a normal time in the registered mobile phone time zone and creating call volume distribution data for each time zone,
An average communication count database for storing the call volume distribution data;
A road map database that registers road maps around each base station of a mobile phone in association with the position of each base station,
A real-time traffic database that stores the actual call volume for each predetermined time zone of the registered mobile phone;
Based on the information in the available mobile phone database, the average communication frequency database, and the real-time traffic database, the call volume of a mobile phone used as a probe terminal in a predetermined time zone increases more rapidly than the normal call volume. Computing means for determining whether or not
When the sudden increase in the call volume is determined, the position of the probe terminal mobile phone that has been called is estimated, and this position estimation involves matching with a pre-registered road map, and the estimated position matches A traffic congestion detection system comprising: a calculation means for estimating a corresponding location as a traffic congestion point when concentrated on a certain location on the road. In a position detection system for detecting the movement position of a specific mobile phone,
A process of identifying two or more base stations that can receive mobile phone radio waves, and subdividing the map matching plane corresponding to the surrounding area of these base stations into a mesh;
Processing for extracting road map information in the peripheral area of the base station identified from road map information registered in advance, and incorporating the extracted road map information into the mesh-like map matching plane; ,
Calculating a distance from the two or more base stations to the mobile phone, and obtaining an intersection of circles with these distances as radii in the mesh-like map matching plane incorporating the road map information; and A mobile phone position detection system that estimates a moving position of the mobile phone by executing the mobile phone.   11. The distance from the two or more base stations to the mobile phone according to claim 10, wherein a difference in radio wave propagation delay time between the plurality of base stations relative to the mobile phone and a radial direction within each communication area of the plurality of base stations. A mobile phone position detection system that is calculated using the radial distance of the band that is divided into two.

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